Adopted values for the reduced electric quadrupole transition probability, B(E2)↑, from the ground state to the first-excited 2+ state of even–even nuclides are given in Table I. Values of τ, the mean life of the 2+ state; E, the energy; and β, the quadrupole deformation parameter, are also listed there. The ratio of β to the value expected from the single-particle model is presented. The intrinsic quadrupole moment, Q0, is deduced from the B(E2)↑ value. The product E×B(E2)↑ is expressed as a percentage of the energy-weighted total and isoscalar E2 sum-rule strengths.

Table II presents the data on which Table I is based, namely the experimental results for B(E2)↑ values with quoted uncertainties. Information is also given on the quantity measured and the method used. The literature has been covered to November 2000.

The adopted B(E2)↑ values are compared in Table III with the values given by systematics and by various theoretical models. Predictions of unmeasured B(E2)↑ values are also given in Table III.

Transition probability from the ground to the first-excited 2^+ state of even-even nuclides

Fusion and breakup of weakly bound nuclei

We describe a sequential (step by step) Darwinian model for the evolution of life from the late stages of the RNA world through to the emergence of eukaryotes and prokaryotes. The starting point is our model, derived from current RNA activity, of the RNA world just prior to the advent of genetically-encoded protein synthesis. By focusing on the function of the protoribosome we develop a plausible model for the evolution of a protein-synthesizing ribosome from a high-fidelity RNA polymerase that incorporated triplets of oligonucleotides. With the standard assumption that during the evolution of enzymatic activity, catalysis is transferred from RNA → RNP → protein, the first proteins in the ``breakthrough organism'' (the first to have encoded protein synthesis) would be nonspecific chaperone-like proteins rather than catalytic. Moreover, because some RNA molecules that pre-date protein synthesis under this model now occur as introns in some of the very earliest proteins, the model predicts these particular introns are older than the exons surrounding them, the ``introns-first'' theory. Many features of the model for the genome organization in the final RNA world ribo-organism are more prevalent in the eukaryotic genome and we suggest that the prokaryotic genome organization (a single, circular genome with one center of replication) was derived from a ``eukaryotic-like'' genome organization (a fragmented linear genome with multiple centers of replication). The steps from the proposed ribo-organism RNA genome → eukaryotic-like DNA genome → prokaryotic-like DNA genome are all relatively straightforward, whereas the transition prokaryotic-like genome → eukaryotic-like genome appears impossible under a Darwinian mechanism of evolution, given the assumption of the transition RNA → RNP → protein. A likely molecular mechanism, ``plasmid transfer,'' is available for the origin of prokaryotic-type genomes from an eukaryotic-like architecture. Under this model prokaryotes are considered specialized and derived with reduced dependence on ssRNA biochemistry. A functional explanation is that prokaryote ancestors underwent selection for thermophily (high temperature) and/or for rapid reproduction (r selection) at least once in their history.

/pdf/the-path-from-the-rna-world-bsie3bxa1v.pdf

The path from the RNA world.

Quantum groups and their applications in nuclear physics

Recent developments in fusion and direct reactions with weakly bound nuclei

We report a case of a 9-year-old boy with glioblastoma with a past history of colon cancer. Germline bi-allelic DNA-mismatch repair deficiency was diagnosed by a lack of immunohistochemical staining for PMS2 in the tumor and normal tissue. Family history was lacking. Sequencing confirmed compound heterozygous PMS2 mutations. A second hit in the DNA-polymerase-ε gene led to complete DNA-replication repair deficiency. This contributed to an ultra-hypermutated phenotype. Temozolomide was excluded from the treatment. PD-1 immunotherapy at recurrence contributed to extending post-relapse survival up to 11 months. Challenges included managing initial immune “flare” related to “pseudo-progression” and access to drug. Family screening diagnosed the sibling with Lynch syndrome. This is the first report of a child with a brain tumor treated with immunotherapy from India. Our report supports the routine inclusion of immunohistochemistry for mismatch repair proteins in the evaluation of pediatric high-grade glioma as this may directly impact the clinical care of these children and families.

Germline Biallelic Mismatch Repair Deficiency in Childhood Glioblastoma and Implications for Clinical Management

The rigidity and flexibility of homologous psychrophilic(P), mesophilic(M) and thermophilic(T) proteins have been investigated at the global and local levels in terms of packing factor and atomic fluctuations obtained from B-factors. For comparison of atomic fluctuations, correction of errors by considering errors in B-factors from all sources in a consolidated manner and conversion of the fluctuations to the same temperature have been suggested and validated. Results indicate no differences in the global values like average packing factor among the three classes of protein homologs but at local levels there are differences. Comparison of homologous proteins triplets show that the average atomic fluctuations at a given temperature obey the order P>M>T. Packing factors and the atomic fluctuations are anti-correlated suggesting that altering the rigidity of the active site might be a potential strategy to make tailor made psychrophilic or thermophilic proteins from their mesophilic homologs.

Insights on Rigidity and flexibility at the Global and Local Levels of Protein Structures and their Roles in Homologous Psychrophilic, Mesophilic and Thermophilic Proteins: A Computational Study.

It is shown that the ''normal'' and ''decoupled'' band-like structures recently observed in the nuclei /sup 133/Pr and /sup 135/Pr can be reproduced within the framework of a standard version of the particle-rotor model. In addition, several positive parity levels in /sup 135/Pr, to which no band assignment could be given earlier, are shown to be the members of two positive parity bands with opposite signatures based on the (3/2/sup +/(411) Nilsson orbital. The most interesting observation of the present work is the near total attenuation of the Coriolis interaction in the positive parity bands in /sup 135/Pr. It is suggested that this nucleus can be a very good testing ground for different versions of the particle-rotor models currently used by different workers.

Band structure in 133,135Pr

The level structure of104Ag has been studied through the103Rh (α, 3nγ) reaction at Eα=40 and 45 MeV. The principal features of the proposed level scheme are in agreement with those obtained earlier through heavy ion reaction. Two quasiparttcle-plus-rotor model calculation has been performed, and the results are compared with experimental data.

Band structure in 104 Ag

An expression for the supercoiling free energy was obtained for a covalently closed circular B DNA in terms of the elastic parameters of the macromolecule. It is well known that this freeenergy source may induce conformational changes, such as the B-Z transition, under physiological conditions. As an extension of our earlier work, a more realistic theory of the supercoil-induced B-Z transition in a Z -transformable stretch, cloned into the closed circular DNA, was developed on the basis of statistical thermodynamics. The results clearly indicate that the transition is cooperative at a critical supercoil density, which may be followed by a continuous elongation of the Z -stretch with increasing supercoiling. The results are found to be in very good agreement with the available experimental data.

S. Sen

Papers

Germline Biallelic Mismatch Repair Deficiency in Childhood Glioblastoma and Implications for Clinical Management

Insights on Rigidity and flexibility at the Global and Local Levels of Protein Structures and their Roles in Homologous Psychrophilic, Mesophilic and Thermophilic Proteins: A Computational Study.

Band structure in 133,135Pr

Band structure in 104 Ag

Theory of a supercoil-induced B-Z transition in closed circular DNA